1. Field of the Invention
The present invention relates generally to apparatus and methods for cooling electronic components, and, more particularly, to apparatus and methods for cooling audio components.
2. Background
Electronic devices use electric energy. Because their efficiency is less than 100%, a portion of the electric energy is converted into thermal energy. In fact, the efficiency of many electronic components is less than 50%, and often much less than 50%. Such devices convert most of the electric energy provided to them into thermal energy.
The thermal energy—heat—must be dissipated outside of the device where it is converted from the electric energy, or the heat will build up, raising the temperature of the device. Heat buildup is undesirable because high temperatures can degrade performance of electronic devices and, when maximum temperature ratings are exceeded, damage or destroy them. The common trend toward denser packaging aggravates the heat buildup problem, because more power is converted into heat in progressively smaller spaces, and because of the increased difficulty of providing good ventilation in small spaces. Automotive and other vehicular audio installations present specially challenging thermal management problems to designers. There are several reasons for these special challenges.
First, space for installing audio equipment is rather limited in a typical vehicle.
Second, efficiencies of audio loudspeakers are generally quite low. Therefore, the loudspeakers convert into heat most of the power delivered to them. Furthermore, the loudspeakers need to be driven by powerful amplifiers. And the more powerful an amplifier is, the more power it dissipates.
Third, temperatures inside a closed vehicle left in the sun can quickly rise into triple digits. When the driver of the vehicle returns to the vehicle and turns on the audio equipment, the temperature of the equipment may already be close to its maximum rated temperature. Additional temperature elevation resulting from the dissipation of electric energy can damage the equipment, or trigger thermal shutdown of the equipment to avoid the damage.
Previous solutions to the thermal management problems in automotive environments usually involved installation of electric fans to improve ventilation and cool the audio equipment. Unfortunately, fans may not perform adequately because of space limitations in a car: it is difficult to find a good location for a fan, i.e., a location from which the fan can drive fresh air at the power-dissipating components. Fans also tend to be noisy. Moreover, when the car is parked in the sun, the fan merely blows hot air at the audio components, and does not provide the desired cooling effect. Furthermore, fans consume electric power and can discharge the car's battery. For this reason, a typical external (add-on) fan is connected through a switch that does not allow the fan to run when the car's engine is not running.
A need thus exists for cooling systems for electronic devices, and particularly for audio components installed in vehicles, that overcome the shortcomings of existing technologies.